High energy photons need to be detected in a variety of applications including but not limited to nuclear science, high energy physics, astronomy, and medical imaging. In many high energy photon (e.g., x-ray, gamma ray or annihilation photon) detectors, information from individual interactions are recorded, including parameters such as the time of the event, the energy of the event, and the location of the event. These parameters are determined through certain processing algorithms applied to the analog signals that the detector generates.
As nonlimiting examples, FIG. 1 shows arrival time difference spectra for a pair of coincident interactions of two high energy (511 keV) photons generated from a positron-electron annihilation event. As will be appreciated by those in the art, the two photons interact in opposing high energy photon detectors aligned with the direction of photon emission. The arrival time of each coincident photon can be determined and then subtracted to form a histogram of the time differences. FIG. 2 shows an example energy spectrum of high energy photon interactions in a scintillation detector in response to irradiating it with 511 keV photons and 1.2 MeV photons from a Na-22 source. The pulse-height of the signal (x-axis) is proportional to the energy of the photon interaction of the detector. FIG. 3 shows spatial distributions of high energy photon interactions in a position sensitive high energy photon scintillation crystal array detector. A high energy photon detector can record position (discrete or continuous) of high energy photon interactions.
However, the transmission of such analog signals for processing can present problems. For example, because several detectors often are used in a given application, many individual signal lines (e.g., wires) are required to carry encoded analog signals. The number of signal lines increases even further for delivering various types of information. Additionally, the quality of the signal may deteriorate, particularly if the detector is located in certain environments (as a nonlimiting example, magnetic environments, such as within a magnetic resonance imaging (MRI) detector), or is multiplexed to reduce number of readout channels.